Population Ecology Flashcards
A group of organisms that can interbreed and produce fertile offspring.
Species
A group of organisms of one species in an area.
Population
A group of organisms of many species in an area.
Community
Factors that define how rapidly a species can reproduce.
Biotic Potential
List 5 aspects of the biotic potential of a species.
A. How long it takes to reach sexual maturity.
B. How likely they are to survive until sexual maturity.
C. The amount of time between reproducing (How often they can reproduce).
D. The number of reproductions in a lifetime.
E. The number of offspring produced in each reproduction.
How can wildlife managers make use of understanding the biotic potential of pest species?
They can take actions to attempt to reduce the biotic potential of the species.
How can wildlife managers make use of understanding the biotic potential of endangered species?
They can take actions to attempt to increase the biotic potential of the species.
What does “r” stand for?
The growth Rate of a population.
Give the equation used to calculate population growth.
r = (b-d) / N
What does each term in the growth rate equation represent?
r = growth rate
b = births
d = deaths
N = original Number in population.
3000 flying squirrels live in the Tahoe basin. 700 adults died last year due to predation by cats and natural predators, accidents with cars, disease, and old age. There were 5000 offspring born last season, but only 500 of these survived to adulthood. Find r for this population.
r = (500-700) / 3000 =
-.067 = -6.7%
If r is a negative number, what does the minus sign show us about the population’s growth?
It shows negative population growth, with the population decreasing.
Give the equation for finding the future size of a population (or a financial investment).
F = I(1+r) ^t
To solve this, start with (1+r).
Next, raising the result to the t power.
Finish by multiplying by I.
What does each term in the future population equation represent?
F = Final Population
I = Initial Population
r = Growth Rate
t = Time in years
Calculate the population of flying squirrels five years from now ( there were 3000 to start with, and they had a growth rate of -.067).
In five years, there will be 2121 squirrels. (If you rounded differently, you may have gotten an answer that was not exactly the same, which is ok. But it should be close to 2100).
What does “K” stand for?
Carrying Capacity
What is carrying capacity?
The largest number of organisms of one species that an environment can support indefinitely.
A rapid increase in a population by a certain percentage each year.
Exponential Growth
A slow increase in a population by a fixed number of individuals each year.
Linear Growth
The death rate of a population.
Mortality
The number of individuals that live to various ages in a population.
Survivorship
The type of survivorship curve shown by organisms such as fish that have many offspring, but few of them survive to adulthood.
Type III, or Early Loss
The type of survivorship curve shown by organisms such as mice that have the same mortality rate in juveniles as they do as adults.
Type II, or Constant Loss
The type of survivorship curve shown by organisms such as humans that have few offspring, with most of them surviving to adulthood.
Type I, or Late Loss
The number of different species in an area.
Diversity
The number of individuals in an area (how crowded it is).
Density
Influences on population growth which limit the population more and more as the population becomes more crowded.
Density-Dependent Factors
Influences on population growth which limit the population the same way in both crowded and non-crowded conditions.
Density-Independent Factors
Species that grow rapidly under ideal conditions - they often colonize new environments.
Opportunists, aka, r-strategists, aka, pioneer species